This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This proposal describes a research program in the development of versatile photosensitizers excitable by Infrared source for photodynamic therapy (PDT) as applied to breast cancer treatment. PDT utilizes a photosensitizer, working as a light-activated drug, to treat the target tissue locally upon the irradiation of light with appropriate wavelengths. One of the key components in effective and efficient PDT is the photosensitizers, so called PDT drugs. The goal of this study is to design and develop photosensitizers toward improving the efficacy of targeted PDT for breast cancer treatment. This study will focus on the photochemical activity and the targeted therapeutic nature of the photosensitizers. We believe that such photosensitizers could potentially satisfy the requirements of an ideal PDT drug and become the next generation PDT drugs. We expect the advancement of PDT drug development will improve the use of PDT for breast cancer treatment.